1. Field of the Invention
The present invention relates to a polishing method of a soft magnetic layer in a thin-film magnetic head having the soft magnetic layer with iron (Fe) alloy that contains silicon (Si) and aluminum (Al), a manufacturing method of a thin-film magnetic head and a thin-film magnetic head.
2. Description of the Related Art
In general, nickel-iron (NiFe) alloy (permalloy) is used as soft magnetic material for a shield layer. In the case of manufacturing a magnetoresistive (MR) effect read head element of a thin-magnetic head by stacking a lower shield layer with permalloy, it is preformed to planarize the surface of the stacked lower shield layer by a chemical-mechanical polishing (CMP). This planarization is preformed to stabilize photo accuracy in forming the MR layer or the lead conductor layer on the lower shield layer.
As the CMP method of permalloy, Japanese patent publication No. 2004-268182A discloses the polishing method which includes, polishing with a acid polish liquid whose pH is more than or equal 1 and less than 7, and then polishing the alkali polish liquid whose pH is more than 7 and less than or equal 14.